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SOME DEVELOPMENTS IN THE DESIGN OF CAVITATION-EROSION FREE PROPELLERS

Discusses some recent developments in the design of propellers that operate under conditions close to the physical limits with respect to cavitation erosion. It is shown that the selection of the radial circulation or pitch distribution should be based not only on its anticipated influence on propeller-induced pressure fluctuation, but also on its effect on efficiency and cavitation. The utilization of blade thickness as a means to delay cavitation is compared with the more commonly known effect of chord length or blade area. The practical importance of increased blade thickness at the tips of wide-bladed or ice-strengthened propellers in regard to strength and stiffness of the blade-edges is emphasized. Some limitations of present day model testing in a cavitation tunnel are illustrated by two practical cases. In one case erosion occurred in spite of successful model tests, in the other case no erosion was observed although the model test results had been alarming in this respect.

Supplemental Notes:

Symposium on High Powered Propulsion of Large Ships, Part 1, December 10-13, 1974, Wageningen, Netherlands. Entire proceedings-2 volumes, 26 papers-available for $21.00.